When one logs in - in this case myself as admin - the notifications in the drop-down on the navbar will have a red circle by the little bell icon to show there is a notification. It was for activating an account which I've done before with others.
But this time I got a notification, activated the account, the red circle is no longer there but the drop-down still shows the notification.
I went to the UCP and there I see the notification but it's whited out enough to show the notification but I'm unable to mark it read or do anything with it. This image shows the UCP.